I think the most embarrassing strawman of Protestantism is how it sees the Catholic view of Justification. In the Protestant's mind, the Catholic position entails a person starting off a little bit righteous, then has to work his way up to fully righteous. It's as if the Catholic had to fill up a gas tank, with the tank starting off at 1% full, and with each good work they increase the tank by 1%, until they get to the end of their life and the tank is 100% full. With this view in mind, the Protestant thinks the Catholic is never actually Justified in this life. As such, this "Catholic Gospel" hardly sounds like good news at all, and in fact is (understandably) seen as quite troubling. But this is a complete misunderstanding of the Catholic view, and if you can point this strawman out to Protestants it will completely pull the rug from under them.
The actual Catholic view is that a Catholic is instantly 100% Justified the moment they convert. This then means that works have nothing to do with a Catholic getting Justified. So it is a complete strawman for the Protestant to say the Catholic view of Justification is a "process" while in 'contrast' the Protestant claims to stand firm on "the finished work of Christ". In the Catholic view, the moment one is baptized (usually as an infant, who obviously doesn't do any work at all), through the merits of Jesus, the individual is instantly 100% forgiven of their sins and instantly becomes an Adopted Child of God. Period. There's no "work" to be done. There isn't really such a thing as "initial justification," so such language should be avoided by all sides, since Baptism is not the start of some progressive life-long filling up of a 'righteousness gas tank'.